In the known devices, German Pat. No. 1,208,535, by which documents are withdrawn from a supply pile and are conveyed separately to a document outlet, there is the difficulty that because of the adhesion existing between document surfaces lying one on another, two or more documents are often taken off at the same time and conveyed to the document outlet. Such a double or multiple document issuance renders impossible any further systematic treatment of the documents, e.g. in the processing equipment arranged in sequence after the document outlet.
In order to prevent any such undesirable multiple conveying of documents, the principle is known, U.S. Pat. No. 1,955,066, of providing a separating roller in the conveying line, which roller rotates counter to the conveying direction, and thereby when two documents lying one on another pass through, it then retains one of these, while the document not in contact with the separating roller is conveyed further without hindrance. It has been found in practice that such a counter-rotating separating roller is often not sufficient to separate reliably double or multiple documents adhering to one another.